Imaging Feedback for Pulsed Cavitational Ultrasound Therapy:Histotripsy.

Cavitational Ultrasound Therapy;Histotripsy;Dose-efficient Treatment for Homogeneous Lesion Production;Imaging Feedback With Backscatter Reduction;Imaging Feedback With Shear Wave Elastography;Imaging Feedback With Shear Wave Propagation Characteristics;Biomedical Engineering;Engineering;Biomedical Engineering

Wang, Tzu-YinXu, Zhen ;

University of Michigan

关键词: Cavitational Ultrasound Therapy;    Histotripsy;    Dose-efficient Treatment for Homogeneous Lesion Production;    Imaging Feedback With Backscatter Reduction;    Imaging Feedback With Shear Wave Elastography;    Imaging Feedback With Shear Wave Propagation Characteristics;    Biomedical Engineering;    Engineering;    Biomedical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/89658/tzuyin_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Histotripsy is a cavitational ultrasound therapy which mechanically fractionates soft tissue into subcellular debris using high intensity short ultrasound pulses. Histotripsy can be an effective tool for many clinical applications where non-invasive tissue removal is desired, including tumor therapy. For non-invasive tissue ablation therapy like histotripsy, image based feedback information allowing for accurate targeting, optimization of the on-going process, and prediction of the treatment efficacy in real time is the key to successful treatments. The overall goal of this research is to develop image based feedback methods that can accurately predict the clinical outcomes during and after histotripsy treatments. To achieve this goal, the research was conducted in two stages. In the first stage, new treatment strategies were investigated to produce homogeneous tissue fractionation. This ensures that feedback metrics obtained with any tissue characterization method are representative of the whole lesion instead of a misleading average of fully homogenized and non-homogenized zones. Specifically, two treatment strategies were developed. A focal zone sharpening technique, which limited the spatial extent of cavitation by preconditioning the cavitation nuclei in the surrounding area, was developed to create highly confined lesions with minimum scattered damage in the lesion boundaries. A cavitation memory removal strategy, which allowed for random distribution of cavitation in response to each therapy pulse, was developed to produce homogeneously fractionated lesions with a dramatically reduced therapy dose. In the second stage, three ultrasound image based methods were investigated to provide quantitative feedback information regarding the degree of tissue damage. These methods included ultrasound backscatter intensity analysis, ultrasound shear wave elasticity imaging, and characterization of shear wave propagation patterns. Strong correlations existed between the quantitative metrics derived from these methods and the degree of tissue fractionation as examined with histology, demonstrating the feasibility of using these metrics as quantitative feedback for histotripsy treatments.In conclusion, this research demonstrates that histotripsy can be a highly controllable tissue ablation therapy via precise control of cavitation. Significant potential exists for histotripsy to be developed into an image-guided modality for noninvasive ultrasound tissue ablation therapy.